Commit 23fc02e3 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 's390-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 

Pull s390 updates from Vasily Gorbik:

 - Add support for multi-function devices in pci code.

 - Enable PF-VF linking for architectures using the pdev->no_vf_scan
   flag (currently just s390).

 - Add reipl from NVMe support.

 - Get rid of critical section cleanup in entry.S.

 - Refactor PNSO CHSC (perform network subchannel operation) in cio and
   qeth.

 - QDIO interrupts and error handling fixes and improvements, more
   refactoring changes.

 - Align ioremap() with generic code.

 - Accept requests without the prefetch bit set in vfio-ccw.

 - Enable path handling via two new regions in vfio-ccw.

 - Other small fixes and improvements all over the code.

* tag 's390-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (52 commits)
  vfio-ccw: make vfio_ccw_regops variables declarations static
  vfio-ccw: Add trace for CRW event
  vfio-ccw: Wire up the CRW irq and CRW region
  vfio-ccw: Introduce a new CRW region
  vfio-ccw: Refactor IRQ handlers
  vfio-ccw: Introduce a new schib region
  vfio-ccw: Refactor the unregister of the async regions
  vfio-ccw: Register a chp_event callback for vfio-ccw
  vfio-ccw: Introduce new helper functions to free/destroy regions
  vfio-ccw: document possible errors
  vfio-ccw: Enable transparent CCW IPL from DASD
  s390/pci: Log new handle in clp_disable_fh()
  s390/cio, s390/qeth: cleanup PNSO CHSC
  s390/qdio: remove q->first_to_kick
  s390/qdio: fix up qdio_start_irq() kerneldoc
  s390: remove critical section cleanup from entry.S
  s390: add machine check SIGP
  s390/pci: ioremap() align with generic code
  s390/ap: introduce new ap function ap_get_qdev()
  Documentation/s390: Update / remove developerWorks web links
  ...
parents 4e3a16ee bfa50e14

Documentation/admin-guide/kernel-parameters.txt

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@@ -3728,6 +3728,8 @@ 
				may put more devices in an IOMMU group.

		force_floating	[S390] Force usage of floating interrupts.

		nomio		[S390] Do not use MIO instructions.

		norid		[S390] ignore the RID field and force use of

				one PCI domain per PCI function



	pcie_aspm=	[PCIE] Forcibly enable or disable PCIe Active State Power

			Management.

Documentation/s390/index.rst

+1 −0
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@@ -15,6 +15,7 @@ s390 Architecture 
    vfio-ccw

    zfcpdump

    common_io

    pci



    text_files

Documentation/s390/pci.rst

0 → 100644
+125 −0
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.. SPDX-License-Identifier: GPL-2.0



=========

S/390 PCI

=========



Authors:

        - Pierre Morel



Copyright, IBM Corp. 2020





Command line parameters and debugfs entries

===========================================



Command line parameters

-----------------------



* nomio



  Do not use PCI Mapped I/O (MIO) instructions.



* norid



  Ignore the RID field and force use of one PCI domain per PCI function.



debugfs entries

---------------



The S/390 debug feature (s390dbf) generates views to hold various debug results in sysfs directories of the form:



 * /sys/kernel/debug/s390dbf/pci_*/



For example:



  - /sys/kernel/debug/s390dbf/pci_msg/sprintf

    Holds messages from the processing of PCI events, like machine check handling

    and setting of global functionality, like UID checking.



  Change the level of logging to be more or less verbose by piping

  a number between 0 and 6 to  /sys/kernel/debug/s390dbf/pci_*/level. For

  details, see the documentation on the S/390 debug feature at

  Documentation/s390/s390dbf.rst.



Sysfs entries

=============



Entries specific to zPCI functions and entries that hold zPCI information.



* /sys/bus/pci/slots/XXXXXXXX



  The slot entries are set up using the function identifier (FID) of the

  PCI function.



  - /sys/bus/pci/slots/XXXXXXXX/power



  A physical function that currently supports a virtual function cannot be

  powered off until all virtual functions are removed with:

  echo 0 > /sys/bus/pci/devices/XXXX:XX:XX.X/sriov_numvf



* /sys/bus/pci/devices/XXXX:XX:XX.X/



  - function_id

    A zPCI function identifier that uniquely identifies the function in the Z server.



  - function_handle

    Low-level identifier used for a configured PCI function.

    It might be useful for debuging.



  - pchid

    Model-dependent location of the I/O adapter.



  - pfgid

    PCI function group ID, functions that share identical functionality

    use a common identifier.

    A PCI group defines interrupts, IOMMU, IOTLB, and DMA specifics.



  - vfn

    The virtual function number, from 1 to N for virtual functions,

    0 for physical functions.



  - pft

    The PCI function type



  - port

    The port corresponds to the physical port the function is attached to.

    It also gives an indication of the physical function a virtual function

    is attached to.



  - uid

    The unique identifier (UID) is defined when configuring an LPAR and is

    unique in the LPAR.



  - pfip/segmentX

    The segments determine the isolation of a function.

    They correspond to the physical path to the function.

    The more the segments are different, the more the functions are isolated.



Enumeration and hotplug

=======================



The PCI address consists of four parts: domain, bus, device and function,

and is of this form: DDDD:BB:dd.f



* When not using multi-functions (norid is set, or the firmware does not

  support multi-functions):



  - There is only one function per domain.



  - The domain is set from the zPCI function's UID as defined during the

    LPAR creation.



* When using multi-functions (norid parameter is not set),

  zPCI functions are addressed differently:



  - There is still only one bus per domain.



  - There can be up to 256 functions per bus.



  - The domain part of the address of all functions for

    a multi-Function device is set from the zPCI function's UID as defined

    in the LPAR creation for the function zero.



  - New functions will only be ready for use after the function zero

    (the function with devfn 0) has been enumerated.

Documentation/s390/vfio-ccw.rst

+97 −3
Original line number Diff line number Diff line
@@ -204,15 +204,44 @@ definition of the region is:: 
	  __u32   ret_code;

  } __packed;



This region is always available.



While starting an I/O request, orb_area should be filled with the

guest ORB, and scsw_area should be filled with the SCSW of the Virtual

Subchannel.



irb_area stores the I/O result.



ret_code stores a return code for each access of the region.

ret_code stores a return code for each access of the region. The following

values may occur:



``0``

  The operation was successful.



``-EOPNOTSUPP``

  The orb specified transport mode or an unidentified IDAW format, or the

  scsw specified a function other than the start function.



``-EIO``

  A request was issued while the device was not in a state ready to accept

  requests, or an internal error occurred.



``-EBUSY``

  The subchannel was status pending or busy, or a request is already active.



``-EAGAIN``

  A request was being processed, and the caller should retry.



``-EACCES``

  The channel path(s) used for the I/O were found to be not operational.



``-ENODEV``

  The device was found to be not operational.



``-EINVAL``

  The orb specified a chain longer than 255 ccws, or an internal error

  occurred.



This region is always available.



vfio-ccw cmd region

-------------------
@@ -231,6 +260,64 @@ This region is exposed via region type VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD. 


Currently, CLEAR SUBCHANNEL and HALT SUBCHANNEL use this region.



command specifies the command to be issued; ret_code stores a return code

for each access of the region. The following values may occur:



``0``

  The operation was successful.



``-ENODEV``

  The device was found to be not operational.



``-EINVAL``

  A command other than halt or clear was specified.



``-EIO``

  A request was issued while the device was not in a state ready to accept

  requests.



``-EAGAIN``

  A request was being processed, and the caller should retry.



``-EBUSY``

  The subchannel was status pending or busy while processing a halt request.



vfio-ccw schib region

---------------------



The vfio-ccw schib region is used to return Subchannel-Information

Block (SCHIB) data to userspace::



  struct ccw_schib_region {

  #define SCHIB_AREA_SIZE 52

         __u8 schib_area[SCHIB_AREA_SIZE];

  } __packed;



This region is exposed via region type VFIO_REGION_SUBTYPE_CCW_SCHIB.



Reading this region triggers a STORE SUBCHANNEL to be issued to the

associated hardware.



vfio-ccw crw region

---------------------



The vfio-ccw crw region is used to return Channel Report Word (CRW)

data to userspace::



  struct ccw_crw_region {

         __u32 crw;

         __u32 pad;

  } __packed;



This region is exposed via region type VFIO_REGION_SUBTYPE_CCW_CRW.



Reading this region returns a CRW if one that is relevant for this

subchannel (e.g. one reporting changes in channel path state) is

pending, or all zeroes if not. If multiple CRWs are pending (including

possibly chained CRWs), reading this region again will return the next

one, until no more CRWs are pending and zeroes are returned. This is

similar to how STORE CHANNEL REPORT WORD works.



vfio-ccw operation details

--------------------------
@@ -333,7 +420,14 @@ through DASD/ECKD device online in a guest now and use it as a block 
device.



The current code allows the guest to start channel programs via

START SUBCHANNEL, and to issue HALT SUBCHANNEL and CLEAR SUBCHANNEL.

START SUBCHANNEL, and to issue HALT SUBCHANNEL, CLEAR SUBCHANNEL,

and STORE SUBCHANNEL.



Currently all channel programs are prefetched, regardless of the

p-bit setting in the ORB.  As a result, self modifying channel

programs are not supported.  For this reason, IPL has to be handled as

a special case by a userspace/guest program; this has been implemented

in QEMU's s390-ccw bios as of QEMU 4.1.



vfio-ccw supports classic (command mode) channel I/O only. Transport

mode (HPF) is not supported.

Documentation/s390/zfcpdump.rst

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@@ -46,5 +46,5 @@ initramfs with a user space application that writes the dump to a SCSI 
partition.



For more information on how to use zfcpdump refer to the s390 'Using the Dump

Tools book', which is available from

http://www.ibm.com/developerworks/linux/linux390.
 
Tools' book, which is available from IBM Knowledge Center:

https://www.ibm.com/support/knowledgecenter/linuxonibm/liaaf/lnz_r_dt.html

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